Controlled-temperature treatments with low-cost, off-the-shelf equipment for bud or seed forcing experiments

Abstract

Inexpensive plug-and-play temperature controllers have recently become available. These allow a chest freezer to be programmed easily to hold a desired set point across a range of biologically relevant temperatures. Installation can be completed in a few minutes using consumer-grade chest freezers. We used these temperature controllers to create five temperature-controlled chambers at 12, 14, 16, 18, and 20 °C. We demonstrated the use of these controlled-temperature chambers with two biologic assays: floral budbreak of peach [Prunus persica (L.) Batsch] stemcuttings and germination of sunflower (Helianthus annuus L.) seeds. We used the budbreak and germination rates at multiple temperatures to estimate base temperatures and thermal time requirements for development.